Construction Gets Smarter
Next Generation Materials Could Change the Way We Build
In an era of astounding technological advances, smart building materials have industry insiders rethinking the basics—and potentially transforming age-old ways of doing things.
Construction staples such as concrete and wood are undergoing exciting advances to transform them into next generation materials that fit modern needs. Emerging fields of science, such as nanotechnology, have been able to strengthen and improve a wide range of construction components, from concrete and wood to plastics, steel and glass.
More commonly associated with healthcare and pharmaceuticals, nanotechnology plays a lesser known—but equally important—role in the construction industry. By manipulating atoms, nanotechnologists create new materials that are lighter, stronger, and more durable. Nanotechnology can do everything from improving fire resistance and energy efficiency, to giving bridges the ability to sense structural weaknesses, Nanomagazine shares.
In the future, nanorobots could even be incorporated into self-healing materials and systems. Today’s nanotechnology may be less exciting than armies of micro robots, but it is no less useful. For example, adding nanoparticles of silver to paint inhibits the growth of bacteria and mildew, keeping buildings cleaner and healthier, UnderstandingNano.com reports. A leveling compound that contains nanopores strengthens tiles and keeps them from cracking. Carbon nanotubes fill cracks in conventional concrete and extend the material’s lifespan by keeping water out of the damaged areas.
New materials for a new age
Concrete is one of the most common building materials on the planet. Without it, most construction projects would screech to a halt. And yet, for all its popularity, concrete is far from perfect. Wind, water, and physical stress chip away at its stability and lead to costly repairs or replacements.
But what if concrete could repair itself? This may sound like a case for that army of nanorobots, but scientists have managed to harness another unlikely helper: bacteria. Smart concrete contains capsules made of biodegradable plastic that are filled with dormant bacteria spores and calcium lactate, CNN reports. When a crack forms in the concrete, water seeps in and the capsules are exposed to water, which causes them to open. The bacteria begin to germinate, multiply, and feed on the lactate. The process causes the calcium to mix with the carbonate ions to create calcite—better known as limestone. This limestone seals the cracks and, like magic, the concrete is repaired without the help of any human hands.
In another next generation development, concrete had become translucent. This new version of concrete uses optical fibres to bring daylight through a solid wall and into an interior space. In addition to allowing a controlled amount of light to filter through, these optical fibres can act as screens that display images on the surface of the concrete wall.
Translucent concrete took off in 2012, when a group of EU-funded innovators launched the Brightwall project. The goal was to create a form of concrete through which light could penetrate. Researchers at DTU Fotonik developed a special optical fibre made of polycarbonate that would work for the project and pass fire codes, the Technologist reports.
The new optical fibre has a polycarbonate center encased in a thin layer of acrylate, more commonly called Plexiglas. Because the materials contain different refractive indexes, light is reflected when it penetrates the fibre instead of being dispersed, which is what naturally happens when light hits concrete, the Technologist explains. As a result, light actually passes through the concrete and out the other side. The technology works in both loadbearing and isolated concrete walls.
These walls may be as wide as 30 cm, but they give the illusion of being much thinner. In fact, you can even see objects behind the concrete, although they appear as shadows. This is because the optical fibres can only transmit light; they are far too small to function like a window. If too much light floods into a room, it can be turned down via an electric filter made of liquid crystal, the Technologist reports.
Wood is also going translucent. In a new take on a classic building material, Researchers at Stockholm’s KTH Royal Institute of Technology have developed a transparent wood veneer that can be mass-produced. The concept has been achieved at the microscopic level in the past, but the KTH project developed the technology on a scale large enough for construction projects.
The KTH website gives the details: First, the lignin—a component of the cell walls—is chemically removed. This transforms the wood into a stunning white color. But, it is not translucent yet. To achieve that, a transparent polymer is added into the white veneer substrate and the optical properties of both components are matched.
KTH reports that the material is ideal for solar cells, since wood is cheap, renewable, and easily obtained. These attributes are particularly important when solar cells cover a large surface area, which is often the case. Transparent wood could even be used for windows or semitransparent façades that let light through while still maintaining a level of privacy. For more details, visit www.kth.se/en.
Cross Laminated Timber (CLT) is another wood material that is getting a lot of attention these days. CLT is an engineered wood product that proponents believe has the potential to rival steel and concrete as the go-to building material of the future. Formed by bonding thin timber boards into layers, CLT is remarkably strong and sturdy. In Europe, wooden buildings already soar as high as 15 stories.
Now, Cross Laminated Timber (CLT) is making its high-rise debut in the United States. A 10 storey residential condo made of engineered wood is going up in Manhattan and a 12 storey mixed-use facility made of engineered wood is being built in Portland, Oregon. These demonstration projects won a combined $3 million in funding from the Department of Agriculture in a contest designed to jumpstart the use of CLT in America.
Switching from concrete to sustainably sourced wood significantly reduces a structure’s carbon footprint, making CLT an environmentally friendly alterative to standard building materials.
When developing construction materials and technologies, many scientists focus on reducing a building’s carbon footprint. One intriguing solution is to use kinetic energy to provide power. The London-based company Pavegen produces a tile that draws energy from footsteps. When pedestrians step on a tile, their weight displaces electromagnetic induction generators, creating a rotary motion that generates off-grid electricity, the company website details. In addition to power production, Pavegen’s flooring system captures information. Every tile is fitted with a wireless API that transmits real-time data on pedestrian movements.
Pavegen has successfully completed over 150 projects worldwide. The company’s tiles can be installed almost anywhere, from airports, train stations, and stadiums to shopping centres and public institutions. One of Pavegen’s highest profile projects is located at Dupont Circle, a bustling pedestrian thoroughfare in the centre of Washington, DC. On any given day, 10,000 people walk over the 240 square feet of Pavegen tiles built into the sidewalk, the company website reports. Each one of these passersby adds more renewable power to the local grid. The project was installed in November 2016. For information visit http://www.pavegen.com/.
Floors are not the only surface that is capturing energy. Underground Power has created a kinetic road. Founded in 2011, the Italian company developed LYBRA, a smart speed absorber that transforms traffic into energy. The system is installed on a stretch of road where traffic must slow down—an exit ramp, for example—and captures the kinetic energy lost during deceleration. This power is distributed to the energy grid using a standard photovoltaic inverter, the company website reports. To produce an equal amount of power with a photovoltaic system, it would take an installation of 80kW that covers an area of 600 square metres. In one roundabout that sees around 10,000 vehicles a day, LYBRA generates 100,000 kWh/year. That is about the same amount of energy that 40 families would use. To learn more, visit http://www.upgen.it/en/.
From energy-producing roads to transparent wood and self-healing concrete, these aren’t your father’s building materials. Age-old construction staples are getting a makeover to make them lighter, tougher, and more environmentally friendly. Concepts imagined only in science fiction just a few years ago have become reality today. Who knows what’s next on the horizon?